The present invention relates to sputtering targets and other metal articles. More particularly, the present invention relates to methods to bond various metals together to form bonded sputtering targets and other bonded metal articles.
There are numerous techniques used to bond two metals together, such as diffusion bonding, explosion bonding, and the like. Typically, these processes involve the bonding of one sputtering target or target blank onto a backing plate and this is done one target assembly at a time. Needless to say, the bonding of one backing plate onto a sputtering target one at a time can be quite time-consuming and costly and further can lead to inconsistent quality control.
Furthermore, bonded targets are often annealed for various reasons, such as to relieve the mechanical stress produced in the bonded materials during bonding, to recrystallize the microstructure of the materials, and generally to obtain the desired metallurgical properties for a sputter target assembly. Typically, annealing is performed under vacuum, in an inert atmosphere, or both, to prevent the introduction of impurities into the bonded materials (e.g., from oxidation) during the annealing process. Vacuum annealing is considerably resource-intensive.
Accordingly, methods to improve upon the bonding process in order to reduce the time and cost of producing bonded sputtering targets and other metal articles are desirable.